Low temperature synthesis of(oxy) nitride

当考虑氮化物作为光催化剂和荧光粉等功能材料时，局部结构的影响，如表面形貌和晶体中的缺陷，远远超过体积性质的平均值的影响。因此，在将氮化物的研究从传统转向新的时候。例如从氮化物作为环境惰性材料的研究到氮化物作为功能材料的研究。有必要从一开始重新评估氮化物合成的方法学。基于以上观点，我们重点研究了氨热法合成功能氮化物相关材料，尤其是光催化剂材料。综上所述，我们成功地在600℃的超临界氨水中合成了结晶度良好的钙钛矿LaTaON2。与固相反应法制备的LaTaON_2相比，氨热法制备的LaTaON_2的光催化性能有所提高。在以氨化钠为矿化剂的超临界氨水中反应前后，产物的形貌和粒度都发生了很大的变化。因此，可以认为该反应是在NH_3-NaNH_2溶液中进行的。该方法可推广到其他氧氮基的合成。

When considering nitrides as functional materials such as photocatalysts and phosphor, the effects of local structures such as surface morphology and defects in crystals are far more significant than those of the mean values of bulk properties. Therefore, when shifting the study of nitrides from the conventional to the new. such as from the study of nitrides as environmentally inert materials to nitrides as functional materials. it is necessary to re-evaluate, from the beginning, the methodology of nitride synthesis. Based on the above perspectives, we conduct our study with emphasis on the synthesis of functional nitride related materials, especially photocatalysts materials, using the ammonothermal method. In conclusion, we have succeeded to prepare LaTaON_2 perovskite with well crystallinity in supercritical ammonia with sodium amide at 600℃. And the photocatalytic properties of LaTaON_2 prepared by ammonothermal method have improved in comparison of LaTaON_2 by solid state reaction. Before and after reaction in supercritical ammonia with sodium amide as a mineralizer, the morphology and particle size was dramatically changed. So it may be considered this reaction proceed in NH_3-NaNH_2 solution as a solvent. This approach could be extended to synthesis of other oxynitrid groups.